.nav{
    display: flex;
    width: 100%;
    flex-direction: column;
    font-size: 0.8rem;
}
.topNav{
    display: flex;
    background: #0066FF;
    color: #fff;
    height: 2rem;
    justify-content: space-between;        
    align-items: center;
    padding:0 10px;
}
.logo{
    color:#fff;
}
.ask_btn{
    border:1px solid #0033CC;
    background: #0066CC;
    color:#fff;
    padding:0.1rem 0.6rem;
    border-radius: 2px;
    font-size: 0.8rem;
}
.top_menu{
    display: flex;
    width: 100%;
    border-bottom: 1px solid #ccc;
    height: 2rem;
}
.top_menu_btn{
    flex:1;
    text-align: center;
    line-height: 2rem;
    color:#333;
}
.top_menu_btn:nth-of-type(2){
    border-left: 1px solid #ccc;
}